Identifying Radius/Diameter

Front

What is the definition of a radius?

Back

The radius is the distance from the center of a circle to any point on its circumference.

Front

What is the definition of a diameter?

Back

The diameter is the distance across a circle through its center, equal to twice the radius.

Tags

CCSS.HSG.C.A.2

Front

How do you calculate the diameter if you know the radius?

Back

Diameter = 2 × Radius.

Tags

CCSS.7.G.B.4

Front

How do you calculate the radius if you know the diameter?

Back

Radius = Diameter ÷ 2.

Tags

CCSS.7.G.B.4

Front

What is the formula for the circumference of a circle using diameter?

Back

Circumference (C) = π × Diameter (d).

Tags

CCSS.7.G.B.4

Front

What is the formula for the circumference of a circle using radius?

Back

Circumference (C) = 2 × π × Radius (r).

Tags

CCSS.7.G.B.4

Front

If the radius of a circle is 5 cm, what is the diameter?

Back

Diameter = 2 × 5 cm = 10 cm.

Tags

CCSS.7.G.B.4

Front

If the diameter of a circle is 14 cm, what is the radius?

Back

Radius = 14 cm ÷ 2 = 7 cm.

Tags

CCSS.7.G.B.4

Front

What is the relationship between radius and diameter?

Back

The diameter is always twice the length of the radius.

Tags

CCSS.7.G.B.4

Front

If a circle has a circumference of 31.4 cm, what is the diameter? (Use π ≈ 3.14)

Back

Diameter = Circumference ÷ π = 31.4 cm ÷ 3.14 = 10 cm.

Tags

CCSS.7.G.B.4